A. Field of Invention
The present invention relates to a pneumatic gun or device which can be adapted to medicate animals in different ways and in different ranges, said gun is for use in mass production settings such as a feed lot processing station.
In feed lots it is common to direct cattle to a work station where they are immobilized. At this point the animal is tagged, dehorned, vaccinated, given injections, given oral dewormers, castrated, and given insect protection poured on its skin (known as "pour on"). This pour on is commonly done using a hand held measuring cup which exposes the worker to toxic chemicals. All these operations are performed by a crew of workers at the rate of as much as 5,000 cattle or more in an eight hour shift.
There is a need for low cost equipment to ease the work load and minimize the exposure of workers to toxic chemicals. Our equipment is modular in design and made of plastic parts thus lowering the cost of manufacture, and it is powered by compressed air thus greatly reducing the effect of delivery of medication for the operator. The medication travels though a closed system from the container to the animal thus decreasing operator exposure to toxic chemicals.
B. Description of Prior Art
Commonly used equipment is hand powered. Typical squeeze type guns are made by Phillips Company of Australia (U.S. Pat. No. 182,110) or Instrument Supplies Co. of New Zealand (NZ Pat. 222692). They include a 2 piece handle which is squeezed to push liquid in syringe out through a hypodermic or oral tube. These hand operated guns tend to cause operator fatigue when used over extended periods. Our company (Diana corporation) has manufactured a non-modular medicating device which is air powered and which has been successful in reducing worker fatigue. The success of this first powered device prompted the development of a low cost plastic molded gun that would be modular so that one set of plastic molds could be used to produce many permutations and thus create an affordable powered doser.
Applicant submits that none of prior patents cover simultaneously the features of 1) a closed system with repeatable dose from a separate tank; 2) adjustable dose; and 3) modular construction.
Kleinwolternick (U.S. Pat. No. 5,015,327) is not a repeater device. It is only a remote hypodermic device. It must have its liquid medication recharged each time. It has no provision for dose adjustment. PA1 Tsujino (U.S. Pat. No. 3,515,130) does not have an adjustable dosage feature, is not contemplated as an oral doser, is not pneumatic powered, nor does it show features making it a low cost modular device. PA1 Stephens (U.S. Pat. No. 3,189,029) is a single shot applicator and is not adjustable in dosage. PA1 Kabbaby (U.S. Pat. No. 4,601,709) is a proportioning device for medication into a larger fluid stream, it is not a multiple doser with adjustable delivery. PA1 Cochrin (U.S. Pat. No. 4,561,856) is not a repeater device. Its use is for controllable slow delivery rate. PA1 Knox (U.S. Pat. No. 3,353,537) is similar to our application but it is a much more complicated construction. They have a separate chamber for compressed gas (27) and two separate pistons for gas and liquid (57 and 60). The design does not contemplate low cost modular manufacturing for multiple use. The adjustment of the dose is a complicated method needing an indicator (97, 95, 94). Such a device can become inaccurate after some use and is inherently dangerous because of possible overdose of medication. The liquid inlet location is an obstacle to ease of handling as opposed to our design with rear inlet.